Synthesis and Characterization of Core-Shell Magnetic Mesoporous Silica and Organosilica Nanostructures

Abstract

Initial results en route toward construction of complex magnetic core-shell silica and organosilica nanotheranostics are presented. Magnetite nanoparticles are synthesized by three different methods and embedded within mesoporous silica and organosilica frameworks by different surfactant-templated procedures to produce three types of core-shell nanoparticles. Magnetite nanoparticles (15 nm in diameter) are embedded within mesoporous silica nanoparticles to produce cell-like material with predominantly one magnetite nuclei-resembling core per nanoparticle, with final particle diameter of ca. 150 nm, specific surface area of 573 m2/g and hexagonally structured tubular pores (2.6 nm predominant diameter), extended throughout the volume of nanoparticles. Two forms of spherical core-shell nanoparticles composed of magnetite cores embedded within mesoporous organosilica shells are also obtained by employing ethylene and ethane bridged organobisalkoxysilane precursors. The obtained nanomaterials are characterized by high surface area (978 and 820 m2/g), tubular pore morphology (2 and 2.8 nm predominant pore diameters), different diameters (386 and 100-200 nm), in case of ethylene- and ethane-composed organosilica shells, respectively. Different degree of agglomeration of magnetite nanoparticles was also observed in the obtained materials, and in the case of utilization of surfactant-pre-stabilized magnetite nanoparticles for the syntheses, their uniform and non-agglomerated distribution within the shells was noted.

Magnetic nanoarchitectures for cancer sensing, imaging and therapy

“…Magnetic core/shell analogues of MSN material (MMSN) are readily obtained by including magnetic nanoparticles during the sol-gel surfactant templated synthesis procedure. [98][99][100][101] Transmission electron micrographs of some of literature-reported MMSN materials are represented on Figure 5, characterized by various pore and particles morphologies. reports of the authors.…”

“…reports of the authors. [98][99][100][101] Moreover, the functionalization can be selectively applied to different surfaces of MSN, i.e. the external surface can be functionalized with one moiety while the surface inside the mesopores can contain another type of functional groups.…”

Tunable Magnetic Hyperthermia Properties of Pristine and Mildly Reduced Graphene Oxide/Magnetite Nanocomposite Dispersions

“…Magnetic nanomaterials attract rising attention in biomedical applications, such as easily controllable targeted drug-delivery vehicles for cancer therapy [1][2][3]. Superparamagnetic iron oxide, i.e., magnetite nanoparticles (MNPs) have great potential for biomedical use (MRI contrast enhancement, targeted drug delivery, etc.).…”

Isothiocyanate-Functionalized Mesoporous Silica Nanoparticles as Building Blocks for the Design of Nanovehicles with Optimized Drug Release Profile

“…To a great extent, the versatility of MSNs is due to their singular geometry, which is characterized by the presence of two distinct domains: The internal mesoporous area and an external surface. While the internal mesopores of the MSNs provide a large volume area for the loading of drugs, the outer surface allows their functionalization with valves [8], ligands [9], or probes [10].…”